In yet another study showing the importance of the vitamin of the year, Vitamin D, lower maternal intake is linked to an increase in wheezing among 5 year olds. The study was done here in New England (in Boston at the Brigham and Beth Israel) where the prevalence of asthma is the highest in the nation.
Now before we get too excited about this study it was epidemological and a dietary recall. It is accepted that a dietary recall study is weak in argument since it is subjective and macronutrient intake estimation can vary widely from actual intake. This study had no direct plasma measurements of vitamin D which would have made for a stronger case. However, this study does add more evidence that vitamin D plays a plethora of roles in the body, far more than scientists can provide biochemical mechanistic explanations for. In this case it is suspected that the known Vitamin D receptors on T-cells and B-cells play a part in modulating the immune system.
The researchers concluded, “…low maternal dietary and total vitamin D intakes during pregnancy are associated with increased wheezing symptoms in children at the age of 5 y. These associations were independent of maternal smoking status and maternal intakes of vitamin E, zinc, calcium, and vitamin D by the 5-y-old children.” I’ve uploaded the entire resarch article here: Wheezing and maternal vitamin D
Some MDs are now prescribing 5000-10000 IUs of Vitamin D3 for marked deficiency. The RDA for Vitamin D is 400 IUs. Study after study is showing this is much too low to prevent clinical diseases. No doubt the RDA for Vitamin D will be modified in the next several years to be much more in the 1000 IU range. Adding a Vitamin D3 supplement (not Vitamin D2, make sure it is cholecalciferol!) during the winter months here in Boston (from November until April) is important. Women planning to get pregnant, or who are pregnant should also have their plasma Vitamin D levels checked!
In Health,
George Mandler
Licensed Acupuncturist & Nutritionist Dietitian
Acupuncture, Chinese Medicine, & Nutrition
Boston, Jamaica Plain, Brookline, Massachusetts